TWI601593B - Titanium dioxide-based ignition flux for arc stud welding - Google Patents

Description

Arc-starting agent for titanium dioxide matrix for arc nailing welding

The invention relates to an arc ignition agent, in particular to an arc ignition agent for arc nail welding.

Arc stud welding is to contact a weld of a fastener to a weld zone of a metal workpiece. After the current is turned on, the fastener is lifted off the metal workpiece to make the fastener. Inducing an electric arc between the metal workpiece, thereby simultaneously melting the welded portion of the fastener and the welding portion of the metal workpiece, and finally applying a pressure to the fastener to press the welded portion of the fastener Into the weld zone of the metal workpiece. For example, the fastener is typically a screw or stud, and the metal workpiece is a metal plate or a metal tube.

In practice, an arc stud welding system device is generally used to assist the joining process. The arc stud welding system device holds the fastener by a welding torch, and when the switch of the arc stud welding system device is activated, the electric current is turned on. When the push-pull mechanism in the welding torch lifts the fastener away from the metal workpiece, an arc is generated, and at the same time, the welded portion of the fastener and the welded portion of the metal workpiece are melted. When the push-pull mechanism releases a force for a predetermined time, the push-pull mechanism will force the fastener to be pressed into the molten pool of the metal workpiece, and finally the joint is formed after the power-off cooling. The above-mentioned nail welding is a high-efficiency fastener joining method, and has been widely used in ship yachts, civil engineering construction, building bridges, mechanical equipment, chemical equipment and electric equipment.

However, for fasteners with larger diameters, it is often necessary to open a small hole in the center of the welded portion and insert an ignition tip into the small hole to easily generate an arc to complete the bonding process. If the arc-inducing junction is not added, it is difficult to cause the arc to be generated, and the fastener and the metal workpiece are not easily melted, and the fastener and the metal workpiece cannot be tightly joined. However, the above-mentioned process of applying the arc-inducing junction is cumbersome and time-consuming, and the manufacturing cost is high, which greatly reduces the welding efficiency and increases the welding cost.

In order to solve the above problems, the present invention provides an ignition flux for an arc-stacked titanium dioxide substrate, which is applied to a metal workpiece without adding an arc-inducing junction to a fastener, that is, Can be directly joined to the tight joint.

The arc-ignition agent for the titanium-arc matrix of the arc-studded welding of the present invention comprises 30 to 55% by weight of titanium dioxide, 30 to 55% of nickel oxide, 10 to 35% of aluminum trifluoride and 5~ 25% nickel difluoride. Thereby, the arc can be easily generated, and the arc bonding can be easily performed on the fastener, that is, the tight joint can be directly completed, and the effect of simplifying the arc nailing welding procedure and improving the joint strength can be achieved.

1‧‧‧Arcing agent

2‧‧‧Metal workpiece

3‧‧‧fasteners

Figure 1: Schematic diagram of the use of the arc-inducing agent of the present invention.

Figure 2: Sectional view of the weldment of Group A1 (same as Group B1).

Figure 3: Sectional view of the weldment of Group A2.

Figure 4: Sectional view of the weldment of Group A3.

Figure 5: Sectional view of the weldment of Group A4.

Figure 6: Sectional view of the weldment of Group B2.

Figure 7: Sectional view of the weldment of Group B3.

Figure 8: Sectional view of the weldment of Group B4.

Figure 9: Sectional view of the weldment of Group C1.

Figure 10: Sectional view of the weldment of Group C2.

Figure 11: Sectional view of the weldment of Group C3.

Figure 12: Sectional view of the weldment of Group D1.

Figure 13: Sectional view of the weldment of Group D2.

Figure 14: Sectional view of the weldment of Group D3.

Figure 15: Sectional view of the weldment of Group D4.

The above and other objects, features and advantages of the present invention will become more <RTIgt; The arc welding agent for nail welding, comprising more than 30% by weight of one active ingredient; the invention further provides an arc nail welding method using the arc ignition agent, comprising providing a fastener and a metal workpiece, An arcing agent for arc stud welding is applied to a weld zone of the metal workpiece, and an electric current is applied to cause an arc to be generated between the fastener and the metal workpiece until the welded portion of the fastener and the metal The welding zone of the workpiece is in a molten state, and a pressure is continuously applied to press the welded portion of the fastener into the welding zone of the metal workpiece.

In particular, the active component of the arc-inducing agent is selected from the group consisting of cerium oxide (SiO ₂ ) and titanium dioxide (TiO ₂ ). For example, 100% cerium oxide or 100% titanium dioxide can be used as the arc-ignition agent; alternatively, cerium oxide and titanium dioxide can be mixed in any ratio for common use. Since cerium oxide and titanium dioxide have the characteristics of low bond dissociation energy, they can be rapidly dissociated under the action of a current to cause arc generation. At the same time, cerium oxide and titanium dioxide have the characteristics of increasing the penetration depth, and thus the welding strength can be improved.

In addition, the arc-ignition agent can further comprise a binary compound, which refers to a compound composed of two different atoms, for example Nickel oxide or aluminum trifluoride. Wherein, the bond dissociation energy of the binary compound must be lower than the bond dissociation energy of the active component, so when the electricity is energized, the binary compound will first dissociate, and the active activity will be decomposed, except that the arc can be easily induced. The arc temperature can be increased, and the penetration depth can be greatly increased by the action of the active component. More specifically, the binary compound may be nickel oxide, aluminum trifluoride, nickel difluoride, manganese oxide, chromium oxide, zinc oxide, cobalt oxide, iron oxide, ferric oxide, or ferroferric oxide. The copper oxydioxide or a combination thereof is not limited in the present invention.

In the present embodiment, 30 to 55% by weight of cerium oxide, 30 to 55% of nickel oxide, 10 to 35% of aluminum trifluoride and 5 to 25% of nickel difluoride are used. The arc-ignition agent may be selected from 30 to 55% by weight of titanium dioxide, 30 to 55% of nickel oxide, 10 to 35% of aluminum trifluoride and 5 to 25% of nickel difluoride as the arc ignition. Agent. According to the above composition and ratio, it is possible to easily generate an arc and increase the arc temperature, thereby further increasing the penetration depth. The arc-inducing agent may be in the form of particles or powder, and may preferably be a uniform fine powder to easily cause generation of a high-temperature arc.

The arc stud welding method of the present invention uses the above-described arc-ignition agent to join the fastener to the metal workpiece. The fastener may be a metal screw, a stud or a nut suitable for welding, etc.; the metal workpiece is usually a metal plate member, or may be a metal tube or the like, which is not limited herein. Before the welding, the fastener and the metal workpiece may be pre-cleaned as needed, for example, to remove surface dirt or grease by a volatile solvent, or to remove surface rust by sandblasting, polishing, or the like.

Next, as shown in Fig. 1, the arc-ignition agent 1 is applied to the weld zone of the metal workpiece 2. Furthermore, the area of the arc-ignition agent 1 is preferably slightly larger than the size of the fastener 3. Wherein, when the fastener 3 is a screw or a stud, the welded portion is usually a tapered surface of the screw or the stud, and when the fastener 3 is a nut, it may be a bottom surface of the nut, etc. And the weld zone of the metal workpiece 2 is usually a flat surface or a curved surface. The arc-inducing agent 1 can be first mixed with a solvent to form a slurry, and then brushed on the welding zone of the metal workpiece 2 with a brush. The arc-ignition agent 1 can also be sprayed directly onto the weld zone 2 of the metal workpiece in a powder form.

After coating the arcing agent, the soldering portion of the fastener is contacted with the bonding portion of the metal workpiece, and a current is applied to the fastener to pass the current through the fastener and to the metal workpiece. When the welding is performed, the metal workpiece can be placed on the ground or fixed on a bracket, and the fastener is held by a welding torch, and a current is applied to the fastener by the welding torch. In the state in which the current is turned on, the fastener is moved away from the metal workpiece, for example, by moving or lifting the welding gun to adjust the distance between the fastener and the metal workpiece. At the same time, an arc is generated between the welded portion of the fastener and the welded portion of the metal workpiece, and the welded portion of the fastener is melted to form a weld pool and the metal workpiece is formed by the high temperature arc. The weld zone melts to form another weld pool. Corresponding to the selected arc-ignition agent component and the diameter of the fastener, parameters such as welding current, welding time and lifting distance can be adjusted to change the melting degree of the fastener and the metal workpiece to meet different application requirements.

When the welding portion of the fastener and the welding portion of the metal workpiece are in a molten state, the two welding pools are in contact with each other, and a pressure is applied to press the fastener and the metal workpiece to fuse the two welding pools to each other. And after the two weld pools are cooled, the welded portion of the fastener is joined to the weld zone of the metal workpiece. For example, the fastener is moved to contact the metal workpiece by the welding torch, and a pressure is applied by the welding torch to tightly engage the fastener and the metal workpiece.

In the above welding process, after the arc-ignition agent is applied, the metal workpiece and the fastener are placed in an inert gas environment, and the subsequent steps are performed under the protection of the inert gas to avoid the The fastener and the metal workpiece generate high temperature oxidation during the welding process. Alternatively, after coating the arc-ignition agent, the weld portion of the fastener and the weld zone of the metal workpiece are covered with a ceramic ring, and the subsequent steps are performed under the protection of the ceramic ring to avoid the fastener. And the metal workpiece generates high temperature oxidation during the welding process.

By using the arc-ignition agent, it is not necessary to perform arc-cutting processing on the fastener The production can directly complete the tight joint, which can improve the welding efficiency and reduce the welding cost. Further, in the arc stud welding method, the arc generating agent can be used to easily generate an arc, and the arc temperature can be increased, thereby further increasing the penetration depth.

In order to confirm that the arc-inducing agent of the present invention can indeed increase the penetration depth, the following experiment was carried out:

(A) using cerium oxide as the active ingredient

In this experiment, cerium oxide was used as the active ingredient, and the arc-ignition agents of Groups A2 to A4 were prepared according to the ratios shown in Table 1 below, and the arc-studded welding test was performed by the method of the present invention, respectively. The group does not use arc ignition agents. In this experiment, M6 nails were used as the fasteners, and a stainless steel plate having a thickness of 2 mm was used as the metal workpiece, and welding was performed by an arc nailing machine. The welding conditions were a welding current of 300 A, a welding time of 0.4 seconds, and a lifting distance of 2 mm. After the welding is completed, the welded specimens of the A1~A4 group are cut out respectively, and the weld bead shape is photographed by a metallographic microscope, as shown in Figures 2~5.

It can be seen from Fig. 2~5 that the group A1 (Fig. 2) without the arc-ignition agent has a low penetration depth, which will result in insufficient joint strength; the group A2 using 100% cerium oxide as the arc-inducing agent (Fig. 3), the penetration depth is obviously improved, and it can be practically applied to the welding of the nails; with the 35% bismuth dioxide combined with the remaining binary compounds of the A3 group (Fig. 4), it can be further improved. Step to increase the penetration depth, thereby greatly increasing the joint strength; and using Group A4 (Fig. 5) of less than 30% cerium oxide, the penetration depth is the same as that of Group A1 without using the arc-ignition agent. Not significantly improved.

(B) using titanium dioxide as the active ingredient

Similar to the content of the above (A) experiment, in this experiment, titanium dioxide was used as the active ingredient, and the arc-starting agents of Groups B2 to B4 were prepared according to the ratios shown in Table 2 below, respectively, and the method of the present invention was carried out. The arc stud welding test, the group B1 does not use the arc starter. The welding conditions were the same as those in the above (A) experiment, and after the welding was completed, the welded specimens of the B1 to B4 groups were respectively cut, and the weld bead shape was photographed by a metallographic microscope, as shown in Figs. 2 and 6-8.

Similarly, it can be seen from Figures 2 and 6-8 that Group B1 without the arc-ignition agent (same as Group A1, Figure 2) has a lower penetration depth, which will result in insufficient joint strength; 100% use Titanium dioxide as the B2 group of arc-ignition agent (Fig. 6), the penetration depth is obviously improved, and it can be practically used in the welding of the nail; the 3rd group of 35% titanium dioxide is matched with the remaining binary compound (Fig. 7). , can further increase the penetration depth, and thus greatly improve the joint strength; and use the B4 group (Fig. 8) of less than 30% titanium dioxide, compared to the B1 group without the arc-ignition agent, the penetration depth There is no significant improvement.

(C) Influence of current intensity

The group C1 of the unused arc-ignition agent was used as the control group, and the arc-ignition agent of the above-mentioned group A3 was used as the group C2 of the experiment, and the arc-inducing agent of the group B3 was used as the group C3 of the experiment, respectively The arc stud welding test was carried out by the method of the present invention. In this experiment, the welding current was adjusted to 400 A, and the other conditions were the same as those in the above (A) experiment. After the welding is completed, the welded specimens of the C1~C3 group are respectively cut, and the weld bead shape is photographed by a metallographic microscope, as shown in Figures 9-11.

For the group that does not use the arc-ignition agent, it can be seen that the welding current is 300A (Group A1, Figure 2) and the welding current is 400A (C1, Figure 9). When the current is increased, the penetration depth is only slightly increased, and it still cannot meet the welding standard. For the group using the arc-ignition agent, the group using the welding current of 300A (Groups A3 and B3, Figures 4 and 7) and the group using the welding current of 400A (Groups C2 and C3, Section 10 and 11)) It can be seen that the penetration depth can be changed by adjusting the current intensity to suit the application.

(D) Effect of fastener size and current intensity

In the present experiment, the D1 and D3 groups in which the arc-inducing agent was not used were used as the control group, and the arc-ignition agent of the above-mentioned Group A3 was taken as the D2 and D4 groups. In this experiment, M4 nails were selected as the fasteners, and the welding currents of the D1 and D2 groups were set to 250A, and the welding currents of the D3 and D4 groups were set to 300A. The other conditions were the same in the above (A) experiment. After the welding is completed, the welded specimens of the D1~D4 group are respectively cut, and the weld bead shape is photographed by a metallographic microscope, as shown in Figures 12-15.

It can be seen from the experimental results that under the welding current of 250A, the group of non-arcing agent (D1 group, 12th sheet) has a low penetration depth, which will result in insufficient joint strength; and the group using arc-ignition agent (Group D2, Figure 13), has a good penetration depth. In contrast, under the welding current of 300A, although the current rise can increase the penetration depth of the group of unused arc-ignition agents (Group D3, Figure 14), the group using the arc-ignition agent cannot be reached ( The penetration depth of Group D4, Figure 15). Therefore, the arc-ignition agent of the present invention can certainly increase the penetration depth while being capable of relatively reducing the required current intensity.

In summary, the arc-igniving agent for arc stud welding of the present invention comprises at least 30% by weight of the active ingredient, and using ceria, titania or a combination thereof as the active ingredient, The arc can be easily generated and the arc temperature can be increased, and the arc-bonding can be directly applied to the fastener, so that the tight joint can be directly completed, and the welding efficiency and the penetration depth can be improved.

In addition, the arc-igniving agent for arc stud welding of the present invention can easily cause the generation of an arc by additionally including the binary compound, and the bond dissociation energy of the binary compound is lower than the bond dissociation energy of the active component. Further achieve the effect of improving welding efficiency.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

Claims (1)

An arc-ignition agent for a titanium-titanium substrate for arc nail welding, comprising 30 to 55% by weight of titanium dioxide, 30 to 55% of nickel oxide, 10 to 35% of aluminum trifluoride and 5 to 25% Nickel difluoride.